Abstract:Cecropins and other related peptides are induced in insects and composed of over 30 amino acids with strong antibacterial activity,which is due to formation of large pores in bacterial cell membranes by their specific secondary structure. Analogs of these peptides which do no harm to eukaryotic cell membrances in lethal concentrations for bacteria have been found in mammalian cells. Owing to their broad antibacterial activity,cecropins and other peptides have brought attention of plant pathologists and medical scientists and been applied to the research of medicine and plant antibacterial infection.

Abstract:Lipases from different resources exhibit three specificities for substrate glyceride:The acyl chain specificity for chain length,unsaturation degree,and positions of double bonds in glyceride;The positional specificity for the position of Sn-1(3)and Sn-2 ester bonds in glyceride;and The stereospecificity for enantiomorphous 1-and 3-ester bond of glyceride,Lipase catalyzes ester hydrolysis and esterification(or transesterification )to prepare monoglyceride,polyunsaturated fatty acid and its ester,and optically active organic compounds，thus it has great potential in fatty oil processing and organic synthesis.

Abstract:Protein-protein and protein-DNA interactions and interaction-mediating structure of both protein and DNA molecules were summarized by combination of structure-function studies on eukaryotic transcription factors and DNA. Coordinate or antagonistic activities occur after protein-protein interactions and DNA binding reactions. Dimerization andcompetition in these interactions are of an universal importance in the regulation of eukaryotic transcriptions.

Abstract:The human mitochondrial DNA (mtDNA)is a 16569 bP closed circular double helix molecule.It codes for 13 subunits of oxidative phosphorylation (OXPHOS ) enzyme plus the structural rRNAs and tRNAs. Over the past years,a number of mtDNA mutations that cause human diseases have been identified,such as blindness,deafness,cardiac failure,and human degenerative diseases. Mitochondrial DNA diseases may be much more common than previously thought.

Abstract:Pyrroloquinoline Quinone(PQQ)is a novel prosthetic group and differs from nicotinamid nucleotides,flavin nucleotides ever studied.In the recent decades,PQQ has been studied in Holland,Japan etc,but it was started studying lately in our country.The discovery, isolation,purification, assay,properities and functions of PQQ are introduced.It is beneficial for further studies of it existence,reaction mechanism, biological properities ,physiological functions and application of PQQ .Studying the new prosthetic group has important significents in theory and practice for the development of enzyme sciences.

Abstract:The newly developed technique of retroviral-mediated gene transfer(RMGT ) which mainly involves the transfecting efficiency and safety aspects of RMGT were discussed.And the characteristics and effects of some exogenous genes which could be used to modify the immunogenicity of tumor cells were also classified and presented.Finally,the problems existed both in RMGT and in the preparation of genetically-engineered tumor cell vaccine were analysed.

Abstract:One of the important progress discovered recently in neuroscience is oscillation and synchronous oscillation in the visual cortex,which raises wide attentions in cognitive society. There are different opinions on its explanation,effect and significance in cognitive science.

Abstract:Several selection methods for positive recombinant baculoviruses havebeen developed in the past years. The traditional plaque morphology difference method has been and will be replaced gradually by new methods based on drug resistance,antibiotic resistance etc,Some methods allow the homologous recombination process to be taken place in E.coli,in Saccharomyces cercoisiae or even in vitro. Owing to the greatly increasing frequency of positive recombinant virus,the stocks of positive recombinant virus are obtained easily. The advantages and disadvantages of each method are discussed.

Abstract:The mutant of human proinsulin gene(A4Glu→Leu) was recombinated to the expression vector and expressed in E.coli with high level.The expression product was purified by Sephadex G-50 gel filtration and converted to the mutant of human insulin by trypsin and carboxypeptidase B.The insulin mutant,purified by DEAE-Sephadex A-25,has an expected amino acid composition.The receptor binding activity and biological activity of this mutant are the same with that of standard porcine insulin.

Abstract:Study and application of europium (Eu) labeled mouse monoclonal antibody (McAb) C₁₇ against carcinoembryonic antigen (CEA) by using a synthesized chelate-N¹-(p-isothiocyanatobenzyl)-diethylenetriamine-N¹,N²,N³, N³-tetraacetic acid Eu is described.The Eu-labeled C₁₇ was separated from excess reagent by gel filtration on a column of Sephadex G-50.The fluorescence and ultraviolet absorption for the fractions were monitored and the curves of fluorescence and the optical density were all the same.The specific activity for the two tubes of the labeled-C₁₇ at the protein peak was 5.2 and 9.8 Eu³⁺/C₁₇ molecule respectively and the recovery of the labeled-C₁₇ was 64%. The labeled-C₁₇ was stable for 6 months at least. The standard curves of time-resolved immunofluorometric assay using the labled-C₁₇ showed excellent linearity and slope and had been used in the assay of CEA in serum.

Abstract:To study the mechanism of the susceptibility changes of cupro-zinc superoxide dismutase(SOD)to proteases induced by reactive oxygen species is the aim of this work. By hydrophobic chromatography,hydrophilic and hydrophobic form of SOD was isolated from SOD modified by hydrogen peroxide or ascorbate-Fe(Ⅲ)system.The hydrophobic form of SOD demonstrated a high proteolytic susceptibility to trypsin and pepsin than both the native and hydrophilic form of SOD.The results suggested that the increased hydrophobicity of SOD might be responsible for its high susceptibility to proteases.

Abstract:The activity of glucoamylase has been investigated in W/O microemulsion of cemtyltrimethyl ammonium bromide/n-pentamol/iso-ctance/water system and compared with that in aqueous solution. It was observed that the optimun temperature and pH of the enzyme decreased,and the maximum hydrolysis rate of starch(V_m)and Michaelis constant(K_m)increased nearly 6 and 3 times,respectively in microemulsion compared with that in aqueous solution.

Abstract:A water soluble schizophyllan (Scl)was isolated from the fungus Schizophyllum commune. Gas chromatography,periodate oxidation,methylation analysis and other experiments showed that the main chains are composed of (1-3 )linked glucose residues one third of which have side chains in position 6.The result of oxidation with chromium trioxide and IR suggested that all residues of Scl are βconfigurations. The conformation of Scl was studied by complex-formation with Congo Red,and by the measurements of optical rotatory and viscosity. Scl mainly a single-helical conformation in water solution at lower temperature. If the side chains are removed by periodate oxidation，the proportion of multiple-helical conformation will increase. The helical conformation changes into disorder coli in acid，base，and at slightly higher temperature.

Abstract:The effect of ganglioside GM₃ on the endogenous protein phosphorylation of human monocytoid leukemia cell line J6-2 cells was studied.Addition of 100 μmol/L GM₃ to the particulate fraction of J6-2 cells enhanced the endogenous phosphorylation of several proteins whose relative molecular mass were 180,87,78,67,43 and 31kD while addition of 100 μmol/L GM₃ to the cytosol fraction of J6-2 cells stimulated the phosphorylation of several proteins whose relative molecular mass were 87 and 56kD,but could inhibit the phosphorylation of 70 and 43kD proteins. Because GM₃ has been reported to be able to induce J6-2 cells to differentiate along the monocyte/macrophage route by long term incubation with GM₃ (up to six days)，so the authors postulated that protein phosphorylation induced by short term GM₃ treatment might be the early signal of differentiation of J6-2 cells.

Abstract:Sex identification of cow embryo in its early stage is very important.It is the premise of the possibility that the technology of seperating and transplanting cow embryo can bring about great economic efficacy. PCR technology is an accurate, speedy and sensitive method in sex identification of cow embryo.Usign the human sex differentiation relevant DNA sequences ZFY and ZFX,two primers are designed and a fragment is amplified from the male or female cow genomic DNA.Then the fragments are cloned into the vector pUC118 and are sequenced. It is found that the fragments from ZFY gene and ZFX gene have 88.2% homologous regions. Upon this，primers and probes can be designed to identify the cow sex sensitively by means of PCR.

Abstract:Degenerate oligonucleotide primers MY 11/9(Manos),GP 5/6(Snijders) were used for in vitro amplification by polymerase chain reaction of a relatively conserved portion of L₁ ORF of HPV.A specific fragment of 394-552 bP and 139-15O bp was amplified by PCR from clinical specimens(cervical carcinoma, genital condylomata,ovarian adenocarcinoma etc.)containing DNA from various HPV types. The digestion pattern of restriction endonuclease Rsa Ⅰ analysis of PCR products by PAGE can be used for typing. This method is simple，sensitive，specific and is suitable for detection and typing for genital HPV types in clinical samples.

Abstract:Electrical communication between the flavin adenine dinucleotide redox centers of glucose oxidase and glassy carbon electrode has been achieved by employing ferrocene immoblized in Nafion membrane.The glucose sensor is made by using bovine serum albumin and glutaraldehyde to immobilize glucose oxidase on Nafion-ferrocene modified electrode. It is further coated by Nafion,which is aqueous solution made from Nafion methanol solution by distilling and is not detrimental to the enzyme but to forstall electrochemically active anionic interferents such as ascorbate and urate from reaching the electrode. The Polymer coating also avoids ferrocene’s leaking and keeps the biosensor from fouling agents. The biosensor responds rapidly to glucose in less than 60 second and its calibration linear curve is from 5.0×10^-4 to 1.3×10^-2mol/L.

Abstract:Amyloglucosdase was coentrapped with glucose oxidase(GOD)in a poly vinyl alcohol membrane.The multi-enzyme membrane was combined with an oxygen electrode to form a bienzyme electrode,which could be incorporated in a flow injection system to determine maltose,Temperature effect and pH effect on the bienzyme electrode system were investigated.The linear respones range for the multi-enzyme electrode was 0.5-35mmol/L of sugar.The entire response cycle was less than 2min.The variation coeffect (CV)was 1.8%.The bienzyme electrode was used semi-continuously for 10 days，at the end of which period its respones to maltoseremained 60% of its initial value. Methods to extend the life time of the bienzyme electrode and to eliminate the interference of coexisting glucose are discussed.

Abstract:The principle,the way to eliminate error and the possibility of detecting cell surface antigen and cellular DNA dual parameter by FCM are introduced.It also gave a simple and practical procedure in measurement andanalysis,This method has been used in many research and work.

Abstract:A convenient,semi-automated flow injection fluoroimmunoassay method has been developed incorporating the flexibility of sample handling of flow injection system containing a immobilized protein A immunoreactor. Protein A can binds the Fc region of most mammlian antibodies at near neutral pH,and the bound antibodies can be eluted from protein A at acid pH.This peculiar property of protein was exploided to separate the antigen bound to antibody and the unbound ones.Experimental variables have been studied and the method has been used to determine the transferrin contents in human serum.

Abstract:The pyrogallol autoxidation method used for superoxide dismutase measurement has been improved by using DTT or Vit C as a terminating agent.The reaction system consists of 50mmol/L Tris-HCl,1mmol/L diethylene-triaminepentaacedic acid,0.2mmol/L pyrogallol, pH 8.20 at 25 ℃ in a total volume of 9ml, one drop(about 50μl)of DTT (100mmol/L)or ascorbic acid (5%) being added to stop the autoxidation reaction.The absorbence at 420nm of the reaction system after terminating the reaction keeps constant for an hour.

Abstract:Using 5′- primers corresponding to leader sequence,3′- primers to constant region,and conventional PCR protocol,only 4 out of 10 variable region cDNAs of the 5 monoclonal antibodies were amplified.A novel protocol was designed and tested which included one more time phase of reaction:94℃ 1 min,37℃ 6-8min,1-3 cycles,with 5′-primer but no 3′-primer.Conventional PCR cvcles started after 3′- primer was supplemented.As a result,all 10 variable region cDNAs were successfully amplified.This novel protocol was named “single primer preincorporation PCR”.

Abstract:The study on the interaction of BPLA₂ with Ca^2＋ by fluorescence spectroscopy indicated that Ca^2＋ was very important to BPLA₂.In the prescence of Ca^2＋ ,the environment around the Trp residue in BPLA₂ became more hydrophobic upon the binding of the substrate to the enzyme,resulting in 9 nm blue shift of the Trp fluorescence emission spectrum. But such a phenomenon was not observed in the absence of Ca^2＋.The experiment indicated that there was a hydrophobic region in BPLA₂ molecule. Ca^2＋ might increase the hydrophobility of this region. Further，it was also found that the binding of Ca^2＋ to the enzyme was related to the single His residue of the enzyme.

Abstract:Many experimental observations show that the fluorescence-disappearance phe-nomenon happens at somatic body,biobody,and other materials. This phenomenon is due to the nonlinear interaction between their surface and the laser. Experimental study on the leaflet of plant shows that fluorescence-disappearance phenomenon is a multiphoton process,and is accompanied with second harmonic generation.During fluorescence-disappearance process,the fluorescence energy is transfered into second harmonic signal partially，after roughly counted，the transfer coefficient is about 2.2%.